README
¶
ezpkg.io/jsonz
Package jsonz is a minimal implementation of json parser and transformer in Go. The
Installation
go get -u ezpkg.io/jsonz@v0.2.0
Parse() function returns an iter over the JSON object, which can be used to traverse the JSON object.
Examples
1. Iterate over the JSON object:
package main
import (
"fmt"
"ezpkg.io/jsonz"
)
func main() {
jsonStr := `{"name": "Alice", "age": 24, "address": {"city": "The Sun", "zip": 10101}}`
fmt.Println("| Path | Index | Key | Token |")
fmt.Println("|------|-------|-----|-------|")
for item, err := range jsonz.Parse([]byte(jsonStr)) {
if err != nil {
panic(err)
}
fmt.Printf("| %v | %v | %v | %v |\n", item.GetPath(), item.Index, item.Key, item.Token)
}
}
Will output:
| Path | Index | Key | Token |
|---|---|---|---|
| 0 | { | ||
| name | 0 | "name" | "Alice" |
| age | 1 | "age" | 24 |
| scores | 2 | "scores" | [ |
| scores.0 | 0 | 9 | |
| scores.1 | 1 | 10 | |
| scores.2 | 2 | 8 | |
| scores | 2 | ] | |
| address | 3 | "address" | { |
| address.city | 0 | "city" | "The Sun" |
| address.zip | 1 | "zip" | 10101 |
| address | 3 | } | |
| 0 | } |
2. Reconstruction of the JSON object:
You can reconstruct the JSON object by iterating over the JSON object and adding commas between the tokens. This is useful when you want to modify the JSON object and write it back to a file.
package main
import (
"bytes"
"fmt"
"ezpkg.io/jsonz"
)
func main() {
jsonStr := `{"name": "Alice", "age": 24, "address": {"city": "The Sun", "zip": 10101}}`
var b bytes.Buffer
var lastTokenType jsonz.TokenType
for item, err := range jsonz.Parse([]byte(jsonStr)) {
if err != nil {
panic(err)
}
if jsonz.ShouldAddComma(lastTokenType, item.Token.Type()) {
b.WriteByte(',')
}
if item.Key.IsValue() {
b.Write(item.Key.Raw())
b.WriteByte(':')
}
b.Write(item.Token.Raw())
lastTokenType = item.Token.Type()
}
fmt.Printf("%s\n", b.Bytes())
}
Will output:
{"name":"Alice","age":24,"scores":[9,10,8],"address":{"city":"The Sun","zip":10101}}
3. Reformat the JSON object:
This example will reformat the JSON object by adding newlines and indentation.
package main
import (
"fmt"
"ezpkg.io/jsonz"
"ezpkg.io/bytez"
)
func main() {
jsonStr := `{"name": "Alice", "age": 24, "address": {"city": "The Sun", "zip": 10101}}`
var b bytez.Buffer
var lastTokenType jsonz.TokenType
for item, err := range jsonz.Parse([]byte(jsonStr)) {
if err != nil {
panic(err)
}
if jsonz.ShouldAddComma(lastTokenType, item.Token.Type()) {
b.Print(",")
}
b.Println()
for i := 0; i < item.Level; i++ {
b.Print(" ")
}
if item.Key.IsValue() {
b.WriteZ(item.Key.Raw())
b.Print(": ")
}
b.WriteZ(item.Token.Raw())
lastTokenType = item.Token.Type()
}
fmt.Printf("%s\n", b.Bytes())
}
Will output:
{
"name": "Alice",
"age": 24,
"scores": [
9,
10,
8
],
"address": {
"city": "The Sun",
"zip": 10101
}
}
About ezpkg.io
As I work on various Go projects, I often find myself creating utility functions, extending existing packages, or developing packages to solve specific problems. Moving from one project to another, I usually have to copy or rewrite these solutions. So I created this repository to have all these utilities and packages in one place. Hopefully, you'll find them useful as well.
For more information, see the main repository.
Author
Documentation
¶
Index ¶
- func Parse(in []byte) iter.Seq2[Item, error]
- func Reconstruct(in []byte) ([]byte, error)
- func Scan(in []byte) iter.Seq2[RawToken, error]
- func ShouldAddComma(lastToken, nextToken TokenType) bool
- type Item
- func (x Item) Format(f fmt.State, c rune)
- func (x Item) GetAltPathString() string
- func (x Item) GetPath() Path
- func (x Item) GetPathString() string
- func (x Item) GetRawPath() RawPath
- func (x Item) GetTokenValue() (any, error)
- func (x Item) GetValue() (any, error)
- func (x Item) IsArrayValue() bool
- func (x Item) IsObjectValue() bool
- func (x Item) String() string
- type Path
- type PathItem
- type RawPath
- type RawToken
- func (r RawToken) Bytes() []byte
- func (r RawToken) GetBool() (bool, error)
- func (r RawToken) GetNumber() (float64, error)
- func (r RawToken) GetString() (string, error)
- func (r RawToken) GetValue() (any, error)
- func (r RawToken) IsClose() bool
- func (r RawToken) IsOpen() bool
- func (r RawToken) IsValue() bool
- func (r RawToken) IsZero() bool
- func (r RawToken) Raw() []byte
- func (r RawToken) String() string
- func (r RawToken) Type() TokenType
- type TokenType
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Reconstruct ¶
Reconstruct is an example of how to reconstruct a JSON from Parse().
func ShouldAddComma ¶
Types ¶
type Item ¶
type Item struct {
Level int // level of indentation
Index int // index in the parent array or object
Key RawToken // optional object "key"
Token RawToken // [ or { or } or ] or , or value
// contains filtered or unexported fields
}
func (Item) GetAltPathString ¶
GetAltPathString returns the path of the item as a string `[0].key[1]`.
func (Item) GetPath ¶
GetPath returns the path of the item as a slice of values. The values are the keys of objects (string) and the indexes of arrays (int).
func (Item) GetPathString ¶
GetPathString returns the path of the item as a string "0.key.1".
func (Item) GetRawPath ¶
GetRawPath returns the path of the item as a slice of PathItem. IMPORTANT: The result slice should not be modified.
func (Item) GetTokenValue ¶
func (Item) IsArrayValue ¶
func (Item) IsObjectValue ¶
type Path ¶
type Path []any
Path is a slice of values. The values are the keys of objects (string) and the indexes of arrays (int).
type PathItem ¶
func (PathItem) Format ¶
Format formats the path item as a string. Use "%+v" to format as "[0]" for array, ".key" for object.
type RawPath ¶
type RawPath []PathItem
type RawToken ¶
type RawToken struct {
// contains filtered or unexported fields
}
RawToken represents a raw token from the scanner.
func (RawToken) GetString ¶
GetString returns the unquoted string value of the token. https://datatracker.ietf.org/doc/html/rfc8259#section-7
type TokenType ¶
type TokenType byte
TokenType represents the type of a JSON token.
const ( TokenNull TokenType = 'n' TokenTrue TokenType = 't' TokenFalse TokenType = 'f' TokenNumber TokenType = '0' TokenString TokenType = '"' TokenObjectStart TokenType = '{' TokenObjectEnd TokenType = '}' TokenArrayStart TokenType = '[' TokenArrayEnd TokenType = ']' TokenComma TokenType = ',' TokenColon TokenType = ':' )
Source Files